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On asphalt overlays and opportunities to rationalize pavement markings

Entire road sections along my commuting routes have had recent asphalt overlays or are being prepared for it. This is part of the national government’s regular maintenance program for roads implemented by the Department of Public Works and Highways (DPWH).

Newly asphalted pavement along the eastbound section of Ortigas Avenue Extension – can you guess how many lanes will fit here?

The previous photo was taken one week ago. This is what the section looks like after the contractor restored the pavement markings. I say restore because these are practically the same 3 lanes prior to the asphalt overlay to the rigid pavement structure.

Pavement marking delineating the traffic lanes, median and gutter

I wonder if the DPWH included bike lanes when they contacted the asphalt overlay and pavement markings for this road. There was none before and the new overlay presented a blank slate to which Class III bike lanes could at least have been provided. There is already an increasing number of bike-to-work traffic along Ortigas Ave. Ext. and the Manila East Road, which connects the large towns of Rizal and serves as one of the major arterials connecting the Province of Rizal to Metro Manila (the other being Marcos Highway).

Asphalt overlays like this provide opportunities to rationalize road space through adjustments to the pavement markings. Granted that there’s significant bus and truck traffic along this road, it is still possible to allocate or at least delineate 1.5m to 2m for cyclists. That should also help in making motorists aware of bike traffic and in the long run influence behavior towards safer travels for all road users.

Some old drawing tools for clothoids

I took some photos of old (vintage if you prefer) drawing tools that I have at our laboratory at the university. We found this in the storage many years ago and people seem to have forgotten about them. Instead of heading for storage or being forgotten or worse, thrown away, we decided to keep them at our laboratory mainly to show our students how certain highway or street curves were drawn in the ‘old days’. I am currently the custodian of this and another set that I have kept at my other office at the civil engineering building.

The wooden box is at my office at UP Diliman

The sign basically translates to clothoid drawing tools made by a company based in Setagaya in Tokyo. There are 14 instruments in the box for clothoid parameter values of A = 20m to 350m.

Opening the box shows slots holding instruments for drawing clothoids or spiral curves

Some of the instruments from the case – the large one on top is for A = 300m and 350m (scale 1:1000)

Comparison of size of instruments for (top) A = 60m and 65m, and (bottom) A = 30m and 35m (scale 1:1000)

Instrument for A = 30m and 35m (Scale 1:1000)

A protractor came along with the set but I assume other instruments such as a compass were used in drawing/drafting the curves.

I shall take photos of the other set when I get to visit the other office. These will be for records purposes as well as for posterity. These are practically museum pieces that are now perhaps rarely if even used.

On roadway expansions and induced demand

We start December with another shared article. Here is another excellent article from Todd Litman about roadway expansions and induced demand:

Litman, T. (November 28, 2021) “The Roadway Expansion Paradox,” Planetizen.com, https://www.planetizen.com/blogs/115395-roadway-expansion-paradox?utm_source=newswire&utm_medium=email&utm_campaign=news-12022021&mc_cid=89cc0b2638&mc_eid=9ccfe464b1 [Last accessed: 12/3/2021]

Note the list of references at the end of the article for further reading.

PAREX or PARES?

Much has already been written and said about the proposal by San Miguel Corporation (SMC) to build an elevated expressway atop (or along the banks) of the Pasig River. The project is called the Pasig River Expressway or PAREX. Although it has caught the attention of the public quite recently, the idea or concept is something that was already brought up and studies even before SMC took it up. I recall seeing this concept and even discussing about this with a close friend who was involved in modeling the traffic for an elevated highway along the Pasig River during the PNoy administration for the Metro Manila Development Authority (MMDA). The MMDA then was chaired by someone who is now a senator of the country. There was apparently no opposition then for this project that probably was dismissed or shelved as it had no takers at the time. Fast forward to the present and the concept was picked up or somehow fell into SMC. The latter did some work on it, pitched it to government and, one way or another, got it approved. Being a major project under a high profile company pitched to a government that went by its “build, build, build” slogan, it wasn’t so difficult to get this hyped.

Opposition to the PAREX comes from a broad mix of professionals, environmentalists and civil society groups who questioned not just the idea or concept but the process that led to government practically giving the green light for this project. Some have countered that perhaps, instead of PAREX there should be PARES. PARES would be a Pasig River Esplanade, inspired by the Iloilo River Esplanade. Maybe this is a better option. Maybe we could even have a tramline along the river if the ROW permits it. Or, perhaps instead of an elevated expressway (with the BRT and bike lane add-ons that were obviously included to soften the image of the tollway) there can be a elevated monorail along the Pasig River. This can be designed to have a minimal footprint and could certainly have branches such as one along the Marikina River. These two options alone provide alternatives that SMC should at least consider and study very well. The options might give the company a way to save face (literally and figuratively).

Is it difficult to understand the phenomena of induced demand?

I’m sharing a recent article that laments about how transport departments in the US seemingly don’t understand the concept and phenomena of induced demand. Is it really difficult to understand or are transport officials including highway planners and engineers deliberately ignoring what’s staring them in the face?

Zipper, D. (September 28, 2021) “The Unstoppable Appeal of Highway Expansion,” Bloomberg City Lab, https://www.bloomberg.com/news/features/2021-09-28/why-widening-highways-doesn-t-bring-traffic-relief [Last accessed: 10/10/2021]

Partially completed road widening along a road in Batangas – was this necessary given the traffic in the area before, during and after this pandemic?

The topic in the article is very much applicable to our own Department of Public Works and Highways (DPWH). The DPWH’s key performance indicators (KPIs) need to change from the typical “kilometers of road constructed” or “lane-kilometers of roads widened” to something like “travel time between points A and B”. Agencies like the DPWH always like to claim they are for solving traffic congestion but we already know widening roads just won’t cut it. It has to be more comprehensive than that and involve the entire transport system rather than just a part (i.e., the road). And it has to be a collaborative effort with various other agencies like the Department of Transportation (DOTr) and local government units. Unfortunately, too, these agencies like the DOTr and those under it, and many (not all) LGUs also like to go at it solo so we end up with piecemeal solutions that are also often out of context.

On the STAR Tollway, some recent photos

A trip earlier this year allowed me to take a few photos of the STAR Tollway. STAR stands for Southern Tagalog Arterial Road, which was what the expressway was before it became a tollway. I have memories of this being a regular highway in the early 1990s. Then, it was still a two lane road and there were even animals walking around and at times crossing the highway. Later, even after it became an expressway, the ROW was still not secured (i.e., fenced) so motorists would regularly encounter animals creating unsafe situations to both.

Approaching the entrance to the STAR Tollway
Toll plaza at the entry
Speed limits – the maximum speed limit is 100 kph while the minimum speed limit is 60 kph. There is an interesting sign just before the speed limits. It states “No overtaking on impulse”.
Typical overpass for traffic crossing the tollway
Rest stop – there are only Petron stations along either direction of the tollway. San Miguel owns Petron and operates the tollway
A typical curve section
Sight distance requirements are satisfied for straight, level segments like this.
Typical off-ramp from the tollway

Noticeable in the photos are the wide medians. These are typically used for expansion (i.e., additional lanes) when the time comes that the capacity of the tollway is no longer enough to cater to the demand. Both the NLEX and SLEX used to have these wide medians that are now part of the motorway. Are there alternate uses or purposes for this median? Perhaps, and this has been done abroad, one could fit bicycle paths there? Or maybe install solar panels to generate power? Or maybe do both?

On the other benefits of cycling – pavements

Here is a very interesting article that tackles a not so obvious benefit of switching to cycling:

Dion, R. (July 12, 2021) Biking’s Billion-Dollar Value, Right Under Our Wheels,” Planetizen, https://www.planetizen.com/features/113986-bikings-billion-dollar-value-right-under-our-wheels?utm_source=newswire&utm_medium=email&utm_campaign=news-07262021&mc_cid=51555c9a39&mc_eid=9ccfe464b1 [Last accessed: 8/4/2021]

To quote: “A strategic switch to biking would dramatically reduce the depth of roads, saving untold billions over the next generation.”

This is relevant from the perspective of highway engineering particularly concerning pavement design, construction and maintenance. It is intriguing, too, since pavement design (and consequently pavement thickness) is not necessarily correspondent to light vehicle traffic volumes. In the Philippines, for example, only heavy vehicles are considered for the pavement load estimation. It is assumed that light vehicle traffic, which compose most of the traffic along roads contribute mainly to pavement weathering rather than structural aspects.

On riders’ perception of safety

The Federal Highway Administration (FHWA) of the US Department of Transportation released some infographics recently to highlight road safety. One very timely and relevant graphic image asks about which facilities make bicycle riders feel safer:

There were some initial reactions when I shared this on social media with one immediately criticizing share-use paths and citing the one along Marcos Highway (stretch under Pasig, Marikina, Cainta and Antipolo) as an example. I quickly explained that the graphic assumes good designs instead of the flawed one along Marcos Highway. In fact, the shared use path is also quite popular in Europe and particularly in the Netherlands where they have many examples of these paths stretching for kilometers that are exclusive to active transport (pedestrians and cyclists). The good designs need to be shared and circulated so people will know about what they look like and learn about their features. These can be adopted and adapted to local situations.

Did you notice the images of cyclists/riders at the top of the graphic? These are important, too, because they provide context in terms of the type of riders who are the targets for infrastructure and campaigns that support and promote cycling across different types of people. Cycling shouldn’t just be for the most fit or the weekend warriors but rather for everyone who could take it up and not just for recreation but for everyday, utilitarian use (e.g., commuting, shopping, etc.).

On how animals can safely cross highways

Here is a quick share of an article regarding animal crossings and roads/highways:

I thought the article was interesting not just because it featured animal crossings but because the very same ideas and design interventions may be adopted for humans as well. Indeed, there will be cost implications but that is only because we have been accustomed to designs that favor car use more than the movement of people. Perhaps we should rethink how we design infrastructure such as our roadways for them to be favoring active transport and employing more nature or environment-friendly features.

Inter-island bridges in the Philippines – Nice to have but not necessary at this time?

A news article came out yesterday, reporting on the shelving of several inter-island bridge projects as well as the progress of only 3 projects include the Panguil Bay Bridge. Many of these projects have been conceptualized a long time ago but were being fleshed out through various feasibility studies.

Bridges fall down the BBB priority list

I’ve written before about these bridges, and had a healthy discussion among friends about the merits and demerits of such infrastructure when there are other, more urgent projects that would probably have higher impacts. One friend was involved in studying the connection between Panay and Negros islands, and had concluded that the cost can be justified by the economic benefits brought about by the bridge. I disagreed, stating the costs could cover modern urban transit systems at least in the major cities of Iloilo and Bacolod.

With limited resources and the likelihood of these projects being funded from various foreign loans make them unpalatable since these will mean more debt for the country. Also, these projects will benefit fewer people compared to other transport projects including modernizing public transportation and building bike lane networks. The latter kinds of projects are for daily commuters whereas the bridges are more for occasional travelers. What do you think?